Multimedia linked scent delivery system

ABSTRACT

A device to deliver various combinations of scents in rapid succession to a user&#39;s nose in conjunction with video graphic images and or sounds. The device consists of an air compressor which forces air through a bank of valves. The valves can be mechanically, electrically or pneumatically actuated. The valves can be of an on/off or proportional flow type. Each valve delivers compressed air to a fragrance holder. The air carries away the scent molecules which have entered the gas phase. This air is then mixed with air from all other fragrance holders, whose inlet valves were open, in the packed column. The final mixture is delivered to the user via nasal tubing and is emitted right below the wearer&#39;s nose. Other devices such as a mask covering the nose or a stand, which the user positions their face next to, can be used to deliver the scent to the user. The scent is then drawn away into a scent scrubber. The invention can coordinate the delivery of scents so that they complement video or audiovisual images being displayed. This is done by utilizing a microprocessor or computer controller which receives the electronic output from the music video producing device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.08/887,622 filed Jul. 3, 1997, now U.S. Pat. No. 5,949,522 issued Sep.7, 1999, which in turn claimed the priority of U.S. ProvisionalApplication Ser. No. 60/021,190 filed Jul. 3, 1996.

BACKGROUND

1. Field of Invention

This invention relates to the production of scents in conjunction withthe display of video images

2.Description of Prior Art

There have been different attempts to produce scent in conjunction withmoving images. The one generalization which can be made is that incontradistinction to this application all other related patents work bydispersing the scent into the air. This would mean that the scent had tobe distributed throughout the entire volume of air of the room in whichthe viewer was seated.

In U.S. Pat. No. 1,749,187 , the viewer sits in a movie theatre whilst ablower disperses scent from a tank into the entire theatre. There can bemore than one tank used so that more than one fragrance is used. Thevalves are either hand operated or driven by solenoids. The actuatingmechanism was a lever which follows precut grooves in the edge of thefilm.

U.S. Pat. No. 2,540,144 describes a system for producing scent inconjunction with images on a television. A signal is encoded into thebroadcast TV signal by using a small focussed light in the originalimage field. The signal is decoded on the receiving end with a decoderwhich then triggers the release of different scents from valvecontrolled containers with the help of a blowing system.

In U.S. Pat. No. 2,562,959, there is a film reader which consists ofphotocells which are activated when the portions of the film withpreprogrammed perforations occur. The activation of the photocells inturn leads to the activation of a mechanical gear and cam system whichthen in turn activates switches. The switches then activate solenoidoperated valves which allows compressed air to enter the designatedscent containing chamber. Then the scent is dispersed into the air.

In the U.S. Pat. No. 2,813,452 there are motor driven cells mounted on awheel. The cells have valves which can be connected to rigid tubingoverriding the cell. The tubing is solenoid activated. The cells areplaced on a rotating table in a predesignated way.

U.S. Pat. No. 2,905,049 describes a system for movie theaters todisseminate scents coordinated with the movies. This system uses a trainof fragrance “batteries”. The batteries are pulled along in apredetermined sequence. When the designated battery comes underneath avalve system the scent from that battery is drawn into the ventilatingsystem and dispersed into the theatre.

In U.S. Pat. No. 3,795,438 another device is described to distributescent into a movie theatre. Again there are scent containing cartridgeswhich are moved into position to be in line with a ventilating system sothat the scent is dispersed. The authors give a wide range of thresholdsfor scent detection 10 exp 4 to 10 exp −3 mg / 100 m3. This wide rangeof concentration underscores the difficulty of maintaining a consistentscent threshold when the scent is to be distributed throughout a room.

In U.S Pat. No. 4,603,030 there is another system of scent cartridgeswhich are lifted one by one from a rotating wheel up to a duct systemwhich blows air through it and then distributes the scent laden air intothe room. The duct connects with a vent system which leads to the backsof theatre seats at a cinema where it is then emitted into the air. Thesystem is computer controlled. The scent is in solid form.

The final U.S. Pat. No. in this list is 4,629,604. This is a multiaromacartridge player. It consists of a partitioned box with individualheating elements for the different partitions which heat the separatescent discs in each partition. The scent discs are mounted on onecartridge which is loaded into the player as one unit. The system iscontrolled by an electronic interface which is connected to a videoplayer.

In U.S. Pat. No. 3,795,438 it is stated the invention is based on therecognition that, in order to obtain a controlled distribution of odour,as little of the odorous substance as at all possible has to beintroduced and the odorous substance has to be quickly removed again . .. This highlights a problem common to all the systems described in thisprior art section. The problem is that all these systems must dispersethe scent into a relatively large space(eg. a room or movie theatre).This puts a great demand on the system.

The first demand is that the system must distribute a relatively largeamount of fragrance into an open space. Because concentrations in thedelivery unit have an upper limit this can only be accomplished by usingrelatively high volumes of scent laden air. The second demand is mixing.The system must deliver the scent uniformly distributed throughout theroom simultaneously to all parts of the room. Anyone familiar withdiffusion and convention phenomena knows that accomplishing this feateven in a modest size room is difficult. The final difficulty is beingable to change over from one scent in the room to a different scent asrapidly as the scenes on the screen change.

SUMMARY OF THE INVENTIONS

The purpose of this invention is to expose the viewer of electronicallyreproduced pictures to combinations of scents which correspond to thescene being shown. More specifically the invention can be used toprovide the user with the specific mixtures of scents which they woulddetect at their nose had they actually been in the scene which is beingdisplayed. Thus the invention provides for an entirely new form ofvirtual reality. The term “olfactory virtual reality” will be used torefer to the function of this patent which is to simulate the aromaticsensory effect of a scene.

The ability to successfully achieve this goal is contingent upon thefollowing unique objects and advantages of this system.

The first object and advantage of this system is its ability to carrymixtures of scents to and then away from the user's nose using anenclosed conduit. The use of a conduit is unique. All prior inventionshave relied upon convection and diffusion through air in an open spacecarry scent to the video viewer.

The second object and advantage of this system is its ability to rapidlychange from one scent to another with a minimum amount of air flow.Because of the use of a closed conduit very small volumes of air cancarry all the necessary scent molecules to the user's nose. Because ofthe small carrier air volumes the rate and duration of scent delivery tothe use's nose can be precisely controlled. Thus the rate of change ofscents can be very rapid. This invention is unique in that the scentsprovided to the viewer can change as rapidly as the video scenesdisplayed to a viewer. No prior inventions can achieve this because openair diffusion and convection is so much slower. In addition removal ofthe scent away from the user is also much slower. Thus prior inventionshave never been successfully used for combining scents with movingpicture viewing.

The third object and advantage of this invention is to provide a systemwhich can be operated in conjunction with a wide range of media. Thisincludes movie theatre projectors, television and VCR players, radio,computer programs (including games, CD ROM images and movies), books(and other text displaying devices), and for use with aromatherapysystems, perfume point of sale in conjunction with video, and perfumeformulation systems.

The fourth object and advantage of this system is the ability to blendmultiple scents together. The blending is unique because of the use ofprecise proportional flow control in a closed conduit system. In thisway the precise mixture of concentrations which are created aremaintained all the way to the viewers nose. No prior art can provide forthis. Each individual scent in the blend can adjusted in magnitude sothat a wide variety of sensory impressions can be created. For examplethe location of a pine tree or fireplace or man holding a drink can beadjusted to seem near or far by adjusting the magnitude of flow of theindividual components in the blend.

The fifth object and advantage is the provision of a unique set ofalgorithms to control the delivery of complex mixtures of scents througha closed conduit system. More specifically the algorithms allow for thesimulation of a wide range of scent producing environments. Thealgorithm enables the system produce the same concentrations of scentsat the viewer's nose which would be produced in the actual scene whichis being displayed at any given time. The algorithms are based onderivations from the physical laws which apply to convection anddiffusion of the scent molecules in the gas phase. Thus these algorithmsallow for the creation of a virtual reality device for scent.

This is the first such virtual reality device which can accuratelyemulate scented environments. This is because it can simulate the scentproduced by a complex environment containing many scent producingobjects. In addition it can simulate the scent produced by an objectbased on complex conditions such the movements of the scented object toor away from the observer. Finally, other features can be emulated suchas the scent the observer detects at different temperatures or differentdegrees of air movement.

The sixth object and advantage is to provide special apparatus todeliver scent filled air directly to the users nose. The inventionprovides for three possible types of nasal interfaces which are in closeproximity to the video viewer's nose. All three interface are unique inthat they not only deliver the scent rapidly to the wearer's nose butthen rapidly withdraw the scent away from the wearer's nose. Theinterfaces are specifically designed to control the diffusion of scentto the wearer's nose.

The seventh object and advantage is to provide a unique mechanism toelectronically count the number of NTSC (National Television StandardsCommittee) signal frames (or other comparable analog video signalconventions) of an incoming video signal. There is no such known system.By utilizing characteristic features of the analog signal train, theindividual frames can be counted. This is used to enable thesynchronization of the video signal with the delivery of scents to theuser. However it can be used in many other applications where it isuseful to count the number of NTSC or comparable analog signal videoframes which have passed.

The eighth object and advantage is to provide for a new multi-arrayvalve system which allows for complex mixture of gas or liquid streams.The multiarray valve system uses dynamic alloy wire to activate a gangarray of flapper valves.

Still further objects and advantages will become apparent from aconsideration of the ensuing description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an overview of the whole system;

FIG. 2 a shows the general scheme of the inlet valve 28 configuration;

FIG. 2 b Shows a specific type of valve system which will be thepreferred embodiment for this system;

FIG. 3 a shows one of the devices for disseminating the fragrance;

FIG. 3 b shows a representation of scent molecules diffusion into aturbulent flow stream;

FIG. 3 c shows the laminar flow stream and coordinates;

FIG. 3 d shows the result of a sample calculation of scent moleculediffusion into a laminar flow stream;

FIG. 4 shows an example of scent concentration across a cross section ofa laminar gas stream;

FIG. 5 a shows the nasal tubing attached to the wearer's head;

FIG. 5 a′ shows a side view of the nasal tubing;

FIG. 5 b shows a diagram of flow through a branched tee fitting;

FIGS. 6-1, 6-2, and 6-3 show an example of a commercial microprocessorwhich could be used in the implementation described in FIG. 6 a;

FIGS. 6 a-1, 6 a-2, and 6 a-3 show the details of the free standingmicroprocessor, 8 bit serial shift registers, DC power switches andtheir interconnections with the valves;

FIG. 6 b shows a generalized block diagram for the sequence of stepswhich any electronic control device would have to follow to control thissystem;

FIG. 7 shows the scent scrubber;

FIG. 8 shows a modification of the main embodiment which allows it to beused in a place where many people view the movie at the same time suchas a public cinema, passenger airplane or drive-in theatre;

FIG. 9 a shows a face mask which fits over the wears nose and mouth;

FIG. 9 b shows a nasal mask whose input also comes from the scent inletand which fits snugly over the wearer's nose including the nostrils;

FIG. 9 c shows a nasal interface that is not physically connected to thewearer but is proximal to wearer's nose;

FIG. 10 a shows an alternate embodiment of the inlet valve which usesflapper type valves;

FIG. 10 b shows a gang of flapper valves which are arranged radiallyaround a center spindle; and

FIG. 10 c shows a flapper valve attached to the center spindle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Overview of operation

FIG. 1 shows an overview of the whole system. Control comes from a freestanding microprocessor 34 that includes an A/D converter that can beinterfaced with either a computer 37 or freestanding video displaydevice 39 or both. These controllers are responsible for controlling thevalves 28 and compressor 30 in the system. The electronic signal whichis used to generate the visual image is accessed by the free standingmicroprocessor 34. These devices are capable of interpreting the videosignal such that the current frame of the movie is always known. Thenusing preprogrammed information the free standing microprocessor 34determines the scent or combination of scents that the viewer is exposedto based on which video image is currently being displayed.

The free standing microprocessor 34 determine the scents that the vieweris exposed to by virtue of their control over a series of valves 28through connected control wires 80. The source of the compressed air isa compressor 30 which is capable of delivering compressed air throughstandard fittings at rates up to 7 liters/minute at pressures rangingfrom 5 to 7 psi. The compressor is normally left in the on state but hasa bleed valve 32 to exhaust excess pressure when the inlet valves 28 arenot open.

The inlet valve 28 which can function as either an on/off valve or as aproportional flow controller. These inlet valves are automaticallyoperated in the preferred embodiment but can also be hand operated inother embodiments. They can be electrically, mechanically orpneumatically actuated. The signal to the valve 28 comes from the freestanding microprocessor 34. The signal from the free standingmicroprocessor 34 is determined by either a video signal fed into itfrom a freestanding video display device 39 or the computer 37.

Each of these valves 28 regulate the flow of compressed air from acompressor 30 to a fragrance holder 48 via a liquid fragrance air inlet42. Each has inlet tubing 24 which delivers compressed air. They arealso of the same type as the tubing leaving the fragrance holder 48 thatis polyethylene or another polymer. The compressed air tubing inlets 24all come from a common compressed air inlet hub 26. The compressed airinlet hub 26 consists of one inlet piece which splits into multipleoutlets each one of which is connected to inlet tubing 24.

When the compressed air is delivered to the fragrance holder 48 it picksup the vaporized scent molecules. The fragrance holder contains liquidfragrance. However a scent impregnated gel can be used in lieu of theliquid fragrance. The scent laden air mixes with the output from anyother fragrance containers 48 whose inlet valves are opened. Theindividual holders connect to scent outlet tubing 14. The scent outlettubing 14 is ⅛ ″diameter polyethylene tubing. However the tubing can bemade from other polymers and can be other sizes. Each one of these tubesends in a one way valve 22 which connects into the packed column 16which converges all the inlets into one outlet. This outlet is the scentinlet 18 for the nasal tubing 20. This tubing wraps around the wearer'shead and passes underneath their nose. It then leads into a scentscrubber 38 which is a box with a charcoal filter which removes thefragrance chemicals from the exhausted air.

The air flow is rapid and thus allows for precise control of the scentswhich the viewer is exposed to throughout the course of the film. Inthis way the viewer can enjoy any type of video presentation enhanced bythe simultaneous exposure to combinations of scents. The specificsequence and combination of scents are designed to emulate the scentsthat one would associate with a given scene. For example during a scenewhich took place in a forest the viewer would also smell a scent whichone might typically smell in a forest.

The system has the capability to provide complex mixtures of scentssimultaneously. Thus during a scene in a movie which took place in acrowded bar the viewer could be exposed to a mixture of scents whichincluded the smell of beer, the smell of cigarette smoke and the smellof perfume or cologne. It can be seen that a large number of possiblecombinations of scents can be presented to the viewer in rapidsuccession in coordination with the change of scenes on the screen.

FIG. 2 The Valve System

FIG. 2 a shows the orientation of the inlet valve 28 with respect to therest of the system. Compressed air comes from a compressor 30. It isdirected through the compressor outlet tubing 31 into the compressor airhub 26. This hub consists of one inlet into a common chamber which hasmultiple outlets each of which feeds a separate inlet tube 24 for eachvalve 28. Thus the hub 26 directs the compressed air through every inlettube 24 which leads into an opened valve 28. On top of each valve thereare two valve electrical contacts 40 which are connected to the freestanding microprocessor 34 by control wires 80. The valves are openedand closed when the controller sets up a voltage across the electricalcontacts 40.

Thus the compressed air travels from the compressor 30 through thosevalves 28 which are activated by the controller. The compressor is alsoactivated by the controller 34. The controller sends a signal via thecontrol wires 80 to a power relay 96 which activates the compressor. Thevalves then deliver the compressed air to the fragrance containers 48via the fragrance air inlet 42. The compressed air travels above theliquid or gel fragrance.

It picks up the molecules of the fragrance which have entered the gasphase and this mixture then exits the fragrance container 48 via thescent outlet tubing 14. The scent outlet tubing 14 is ⅛″ diameterpolyethylene tubing. However the tubing can be made from other polymersand can be other sizes. Each one of these tubes ends in a one way valve22 which connects into the packed column 16 which combines the outputfrom all the inlets into one outlet.

The valve 28 can be of many different types including solenoid,pneumatic and motor actuated. The valve can be an on/off type such asthat found in the solenoid valve or it can a proportional flowcontroller that would be motor actuated. In the next section a specifictype of valve will be described for the preferred embodiment.

FIG. 2 b. Shows a specific type of valve 28 which will be the preferredembodiment for this system. The valve can be made out of any solidmaterial including plastic, metal or composites. The outer body of thevalve is a hollow cylinder 78 with an o.d of 1.5 cm and i.d of 1.2 cm atits ends. Inside the cylinder there are two places where the internaldiameter of the cylinder is smaller. These are labelled 75, 77 and willbe called shaft supports. They support the valve stem 70. Each is 0.5 cmthick. Each is located 1.5 cm from the nearest end. Their internaldiameters are 0.25 cm.

They have multiple perforations 79 each 0.1 cm in diameter to allow thepassage of compressed air through the valve 28. The valve stem 70travels through the center of the shaft supports 77, 75. The springloaded stem 70 has a tip which fits into valve seat 72. The stem spring74 is seen around the stem. The spring loaded stem 70 is held firmlyagainst the valve seat 72 by the stem spring 74. In this figure the stemspring is bounded in its long axis on the left side by the shaft support75 and on the right side by the spring support 77.

The spring support 77 is actually part of the stem 70. It is a thinannular extension of the stem 70 which is 0.2 cm thick and has adiameter of 1 cm, thus leaving 0.1 cm clearance to the inside wall ofthe cylinder 78. When the stem spring 74 is made such that itsuncompressed length is 25% longer than the distance from the stemsupport 75 to the spring support 77 when the stem 70 is fully extended.The stem is fully extended when its tip 73 sits firmly in the valve seat72. Thus under normal conditions the stem spring 74 holds the stem tip73 firmly against the valve seat 72. The valve seat 72 is machined fromthe end of the hollow cylinder 78. Its dimensions are shown in FIG. 2 b.This keeps the valve normally in the closed position. In this positioncompressed air cannot flow through it.

One end of the cylindrical sleeve 78 is connected to the fragrance airinlet 42. The other end is connected to the inlet tubing 24 whichdelivers compressed air from the compressor. The direction of compressedair flow is from the inlet tubing 24 through the valve seat 72 on theright through the body of the valve through the perforations 79 in thestem support 75.

The end of the stem 70 opposite the end which sits in the valve seat 72has a dynamic alloy wire 76 soldered to it, such as the Flexinol (R)alloy wire. The other end of the wire 76 is attached to nonconductinggrommet which is in turn glued or fixed in another way to the end 81 ofthe valve 28. The alloy wire 76 is electrically actuated by a conductingwire 80 a, via an electrical contact 40, which travels through a hole inthe end of the sleeve 78 and attaches to the alloy wire near itsconnection to the nonconductive grommet. The other end of the controlwire 80 b is attached to the body of the valve 78 which in the preferredembodiment is made from a conductive material so that a circuit is madewith 80 a. The current goes from 80 a through the alloy wire 76 into thevalve stem 70 to the cylinder 78 via its contact with the stem spring74.

The alloy wire 76 has the property that when it carries an electricalcurrent it contracts and thus exerts a force. In the preferredembodiment a 0.006″ diameter alloy wire 76 is used. When it is activatedwith 400 mA DC current it contracts and exerts a force capable oflifting 330 grams. This force opposes the force of the stem spring 74.Thus it pulls the spring loaded stem 70 off the valve seat 72 whichcorresponds to approximately 4% change in alloy wire 76 length. Thisopens the valve and allows compressed air pass through. When the currentis stopped the alloy wire 76 relaxes and the spring 74 pushes the stem70 against the valve seat 72 which closes the valve 28.

FIG. 3. The Fragrance Holder

FIG. 3 a. shows the fragrance holder 48. The dimensions of the containerare shown in the figure. The container is 3 cm in height 1.5 cm wide and6 cm long. The bottom 1 cm of the vertical height of the container isfilled with the liquid fragrance. Therefore the area in which the airpicks up the scent is 2 cm by 1.5 cm.

The side of the fragrance holder 48 has a fragrance air inlet 42 whichis fed by the tubing coming from the inlet valve 28. Air passes throughthe up the vaporized liquid fragrance 46 at the top of the central well.The scented air exits the fragrance holder via the outlet port 50. Ascent impregnated gel covered with a gas permeable membrane can be putinto the fragrance holder 48 in place of the liquid fragrance.

There are two types of flow patterns that are possible in the fragrancechamber. One is turbulent flow, the other is laminar flow.

FIG. 3 b. Turbulent Flow

FIG. 3 b shows an idealized view of a liquid A evaporating into a gasphase B where the flow is turbulent. The gas stream is moving parallelto the surface of the liquid. The vertical axis represents theconcentration of A in the gas phase. The horizontal axis labelled zrepresents the distance from the gas liquid boundary layer. Onestipulation of turbulent flow is that the Reynolds number falls into theturbulent flow range (i.e.Re>2100). The other assumption is that the gasstream is always well mixed.

The gas phase in the fragrance container 48 includes a stagnant layer ofthickness z2−z1. The concentration profile of A in the mixture of A andB in the stagnant layer from z1 to z2 is shown. The region where z>z2 isthe bulk flow zone where the flow rate of the gas phase B is rapid. Theconcentration of A in the bulk flow zone corresponds to theconcentration of the scent A in the gas which exits the fragrance holder48. The derivation of the concentration profile of A in the stagnantlayer and the concentration of fragrance A in the bulk stream ispresented here.

Let the bulk flow rate of the compressed gas into and out of thefragrance holder 48 be represented by the variable Fg. At the flow rateFg=0 and temp of 25C the concentration the gas phase above the liquid isequation :

Ca (max)=(P/760)(273/298)(M/22.4)=(P)(M)(5.38×10exp-5)g/L

where Ca(max)=maximum concentration of A

P=vapor pressure of A

M=molecular weight of component A

The expression Ca(max) is used because it represents the maximum gasphase concentration attainable at the given temperature.

However the actual calculation of the bulk stream concentration of Ca isnot so straightforward because the flux of fragrance A and the bulkconcentration of fragrance A (Ca) are linked variables. That is the fluxis dependent on the concentration at the boundary layer bulk flowinterface.

The flux of A with respect to the z axis is given by equation 1:

Naz=−cDab (dxa/dz)+xa (Naz+Nbz)S

where the first term is flux resulting from diffusion and the secondterm is flux resulting from bulk molar flow. But component b thecompressed air, is not involved in flux at the fragrance/gas interfaceso Nbz is zero. Then solving the above equation for Naz gives:

Naz=−(c Dab/(1−xa)) dxa/dz

But since the flux is constant then : dNaz/dz=0 thus:

d/dz ((cDab/(1−xa))dxa/dz)=0

c and Dab are constant with respect to the z axis this leads to equation2:

d/dz(1/(1−xa)dxa/dz)=0

integrating twice gives:

ln(1−xa)=C1(z)+C2

using the boundary conditions:

z=z1 xa=xa1

@z=z2 xa=xa2

Let xb=1−xa; xb1=1−xa1, xb2=1−xa2. Then substituting the boundaryconditions in and solving for C1 and C2.

C1=ln(xb1/xb2)/(z2−z1)

C2=−(z1/(z2−z1)ln(xb1/xb2)−ln xb1

Substitution of the expressions for these two constants leads to anexpression for xa which will be referred to as equation 3:

((1−xa)/(1−xa1)=((1−xa2)/(1−xa1))^([(2-Z1)/(z2-z1)])

since xb=1−xa

((xb)/(xb1)=((xb2)/(xb1))^([(z-z1)/(z2-z1)])

going back to the flux equation: Naz (@z=z2)=−cDab/(1−xa)dxa/dz but1/(1−xa)dxa/dz=C1=ln(xb1/xb2)/(z2−z1) this leads to equation 4, which isthe equation for flux at z=z2:

Naz=cDab ln(xb2/xb1)/(z2−z1)

or

Naz=cDab ln((1−xa2)/(1−xa1))/(z2−z1)

Assuming an ideal gas mixture c is constant and Dab is virtuallyconstant.

Thus the flux can be calculated by the above equation if theconcentration in the bulk (xb2) is known. This of course will be theindependent variable. That is the xb2 will be the desired finalconcentration of scent which is delivered to the individual using thesystem.

But xa can be related to the concentration of A in the vapor phase:$\begin{matrix}{{xa} = \quad {{{Moles}\quad {A/{Total}}\quad {Moles}} = {( {{( {{Mass}\quad A} )/{molec}}\quad {wt}\quad A} )/({Nt})}}} \\{= \quad {{( {{Ca}\quad {Vb}} )/{MWa}}/({Nt})}}\end{matrix}$

The mass of fragrance in the container 48 at time t can be described bya mass balance equation. The mass of fragrance in the container at timet is the result of three components:

a) the mass in the container just prior to time t;

b) the flux of fragrance into the gas phase just prior to time t;and

c) the convection of fragrance out of the container just prior to timet. Let the times at which fragrance concentration is calculated berepresented by ti where i=0, 1, 2, . . . n.

Let the time interval between ti and ti+1 be represented by dt. Then thefollowing equation represents the mass balance:

Concentration in gas phase (at time=t−1)×Gas Volume+Fragrance Flux fromLiquid into Gas (at time=t−1) dt−Gas Flow Rate (at time=t) xConcentration(t−1)dt=Fragrance Concentration (at time=t)×Gas Volume

which is expressed symbolically as

Ca(t−1)Vb+Na(t−1)A dt−Ca(t−1)(Fg)dt=Ca(t)Vb

where:

Fg represents the flow rate for compressed air through the container.

then this leads to equation 6.

Ca(t)=(Ca(t−1))+(Na(t−1))(A)dt/Vb−((Ca(t−1 ))Fg dt)/Vb

as dt approaches 0 the error in this equation approaches zero. When thevalve to a specific fragrance container is opened there is a transientunsteady state period . This is the period before the term Ct converges.In this period the value of Ca(t) can be solved for by an iterativeprocess. The process is begun by using known initial values. When t=0,Ct=Ca(max) which is the concentration of fragrance A when the gas phaseis in equilibrium with the liquid phase. At equilibrium the flux term Nwill be zero.

Then iteration begins by incrementing t (time). The key to performingthe iteration is to use the values of Ca(t) from the prior iteration tocalculate the current value of Ct. More specifically by using Ca(t-1)all the terms on the right side of this equation are immediately knownexcept for Na(t-1). But it was shown earlier that Na(t-1) can becalculated from xa2(t-1). The variable xa2(t-1) can be calculated fromCa(t-1) the concentration of Ca in the bulk obtained from the prioriteration by equation:

xa2(t−1)=(Ca(t−1)Vb)/Mwa/NT

Then all the terms for time t−1 can be calculated and then the term Ctcan be calculated. The iteration is continued until their is convergencein the value of Ct. After the transient phase the steady state conditionis reached. In the steady state condition the concentration of fragrancein the gas phase remains constant over time. Referring back to equation6:

Ct=(Ct−1)+(N(t−1))(A)dt/Vb−((C(t−1))Fg dt)/Vb

The following simplification occurs when C(t−1)=C(t):

Na(t)A=Ca(t)Fg

now substitute the following two relationships:

Naz(@z=z2)=cDabln(xb2/xb1)/(z2−z1)

Ca(t)=xa2(Nt)/Vb

then the equation becomes:

cDab A[ln(xb2/xb1)/(z2−z1)]]=xa2(Nt)Fg/Vb

solving for Fg:

Fg=c Dab A[ln(xb2/xb1)]Vb/[xa2(Nt)(z2−z1)]

substituting xb=1−xa:

Fg=c Dab A[ln(1−xa2/1−xa1)]Vb/[xa2(Nt)(z2−z1)]

but

c=total moles/unit volume

and

Nt/Vb=total moles/unit volume

so the equation simplifies to:

Fg=Dab A[ln(1−xa2/1−xa1)]/[xa2(z2−z1)]

The final problem which must be solved before this equation can becalculated is to determine Dab the diffusivity of the scent A in thecarrier gas B. This constant is not always readily available. Analternative is to calculate diffusivity based on the critical propertiesof the two gases. For dilute gas pDab/(pcApcB){fraction (1/3)}(TcATcB){fraction (5/12)} (1/MA+1/MB)^(½)=a[T/(TcATCB)^(½)]^(b)(Slattery JC, Bird RB, AICHE Journal,4,137-142(1958)) for nonpolar gaspairs:

a=2.745×10⁻⁴

b=1.823

Once the mole fraction of A which is to be delivered to the user hasbeen chosen then the appropriate gas flow rate Fg to use can becalculated. That is because all the variables on the right side of theequation are determined. The variables c,D are physical properties ofthe fragrance, A is the surface area of the liquid fragrance, Vb is thevolume of the vapor phase in the fragrance container 48. The term xa1 isthe mole fraction of A at the gas liquid interface of the fragrance A.But at this interface the gaseous form of fragrance A and liquid formare in equilibrium thus the partial pressure its vapor pressure and theterm xa1 is: xa1=vapor pressure of A/Total pressure=pa/pt.

The term xa2 the mole fraction at the gas stream interface is the sameas the mole fraction of A in the gas stream assuming adequate mixing. Ofcourse the concentration is related to mole fraction by xa2=Ca/(Ca+Cb).This concentration should be the same as the final desired concentrationthat is presented to the user's nose assuming adequate mixing. Thus theconcentration of fragrance delivered to the nasal tubing can becontrolled by regulating the gas flow rate Fg.

EXAMPLE I

The following is an example of using the equation derived to determinethe gas concentration of A for a given gas flow rate. For simplicity asingle component liquid will be considered. The liquid in this exampleis n-pentane. Let the temperature inside the fragrance container be 1atm and the temperature be 21C atypical room temperature. The carriergas in this and in all cases will be air. First the diffusioncoefficient for n-pentane in air will be calculated.

pDab/(pcApcB)^(⅓)(TcATcB)^({fraction (5/12)})(1/MA+1/MB)^(½)=a[T/(TcATcB)/^(½)]^(b)

Dab=[a/p][T/(TcATcB)^(½)]^(b)(pcApcB)^(⅓)(TcATcB)^({fraction (5/12)})(1/MA+1/MB)^(½))

a=2.74533 10⁻⁴

b=1.823

p=1 atm

for n-pentane

pcA=33.3 atm

Tc=469.69 K

MA=72.15 gm

Air consists of two major components O2 and N2 the pseudocriticalproperties are calculated as follows:

pc′=Sum xipci Tc′=Sum xiTci

These calculations are described in the following reference: Hougen OAand Watson KM, Chemical Principles. Part III, Wiley, NewYork(1947)pg.873

for N2

pc=33.5

Tc=126.2 K

for O2

pc=49.8 atm

Tc=154.58 K

The average molecular weight of the mixture of N2 and O2 in air is 28.8gm.

Then the pseudocritical properties for air are then:

Tc=131.876 K

pC=36.76 atm

substituting all these values into the equation for the diffusioncoefficient leads to a value of Dab=0.0872 cm²/sec

Now we will calculate the mole fraction of A in the gas stream exitingthe fragrance chamber based on the gas flow rate. For this example thesmallest gas flow rate which will reliably produce turbulent flow willbe used. For tubing with a radius of 1 cm a gas flow rate of 500 cc/secwill produce flow with a reynolds number of 2143.Thus this is the lowestgas flow which will produce turbulent flow in a smooth tubing system.

The expression for requisite gas flow for a given final concentrationis:

Fg=Dab A[ln(1−xa2/1−xa1)]/[xa2(z2−z1)]

Solving for the final concentration of A in the gas stream as a functionof flow rate is more difficult. However one of the final gasconcentration terms xa2 can be separated:

xa2=(Dab A/h(Fg)[ln(1−xa2/1−xa1)]

where h=z1−z2=2 cm

Although the term xa2 is on both sides of the equation a numericalsolution can be achieved wherein a first approximation for xa2 isinserted into the right side of the equation and then used to calculatethe next value of xa2 on the left side of the equation. This iterativeprocess is continued until there is convergence in the value of xa2.This procedure is encoded in the following program, written in theMATLAB language:

PROGRAM I function y=conc(fg,h,A,Dab,xa) %conc to calculate theconcentration %in the turbulent gas stream for a specified flow %hheight of stagnant column %Dab is diffusivity %xa mole fraction at equilxx=0.5; xy=0; while abs(xx−xy)>0.05 xy=xx;xx=((Dab*A)/(fg*h))*(log((1−xy)/(1−xa))); end for i=1:20 y(i)=xx; endBased on the description of the fragrance container given in FIG. 3a thefollowing values were used in the program: A=3.0cm² z2−z1=2cm Dab=0.0872cm²/sec(as calculated in example I) xal = vapor pressure pentane/totalpressure = 520mmHg/latm = 0.6842 Fg=500cc/sec

substituting these values into the listed program yields the followingvalue for xa2:

xa2=0.1813×10⁻³

This is the uniform concentration throughout the exiting gas because theflow is sufficiently turbulent to cause rapid even mixing of the scentmolecules with the compressed air.

FIG. 3C. Laminar Flow

In this section the mathematical equations that describe theconcentration of scent molecules in the case laminar flow will bederived. It is important to perform this derivation because there aremany cases when it is desirable to use laminar rather than turbulent gasflow. For example it will be shown in this section that laminar flowthrough the fragrance container maximizes the uptake of scent molecules.This in turn leads to a higher concentration of scent delivered to theuser.

Secondly in the preferred embodiment the compressed gas source is asmall diaphragm pump with a maximum output of air at 7 psig and 4liter/min. This pump provides for uncontaminated air flow which issuitable for human use as well. The pump also has the advantage of beingquiet which is desirable in consumer applications.

FIG. 3 c shows the laminar flow case. In order to derive theconcentration of scent molecule as a function of the x and z coordinatesfirst it is necessary to write a mass balance equation over a volume ofinterest. The direction of flow is the z direction. The x axis spans thecross section of the fragrance chamber. The subscript A refers to thescent molecule , subscript B represents the component Air. Even thoughair is primarily a mixture of two different molecules it will berepresented by one variable : B . This is because in the prior section,the diffusivity of air was calculated on the basis of the pseudocriticalproperties of nitrogen and oxygen. Thus as far as equations ofcontinuity and mass balance are concerned air can be treated as onecomponent molecule.

The mass balance equation for the scent molecule can be calculated bytaking the derivative of the mass flux in the x and z directions:$\begin{matrix}{{{\partial\frac{Naz}{\partial z}} + {\partial\frac{Nax}{\partial x}}} = 0} & (1)\end{matrix}$

Next the expressions for the net molar flux of the scent molecule A inthe z direction is: $\begin{matrix}{{Naz} = {{{{- {Dab}}{\partial\frac{ca}{\partial z}}} + {x_{a}( {{Naz} + {Nbz}} )}} \approx {{ca}( {v_{z}(x)} )}}} & (2)\end{matrix}$

This simplification occurs because the diffusion of component A in the zdirection is negligible with respect to the net gas flow. Next theexpressions for the net molar flux of the scent molecule A in the xdirection is: $\begin{matrix}{{Naz} = {{{{- {Dab}}{\partial\frac{ca}{\partial z}}} + {x_{a}( {{Naz} + {Nbz}} )}} \approx {{- {Dab}}{\partial\frac{ca}{\partial z}}}}} & (3)\end{matrix}$

This simplification occurs because the mass flux of component A in the xdirection is negligible.

Then substituting these expressions for molar flux into the mass balanceequation (equation 1 in this section) yields: $\begin{matrix}{{v_{z}\frac{\partial{ca}}{\partial z}} = {{Dab}\frac{\partial^{2}{ca}}{\partial x^{2}}}} & (4)\end{matrix}$

Next it is necessary to derive an expression for the gas velocitythrough a rectangular channel as a function of x and z coordinates. Thiscase has been derived in the transport phenomena literature (TransportPhenomena. Bird, Stewart and Lightfoot pgs.538-539 John Wiley and Sons.1960). The equation for Vz is: $\begin{matrix}{{Vz} = {\frac{( {{Po} - {Pl}} )B^{2}}{2\mu \quad L}\lbrack {1 - ( \frac{x}{B} )^{2}} \rbrack}} & (5)\end{matrix}$

But the expression for net flow fg: $\begin{matrix}{\frac{3{fg}}{4{WB}} = \frac{( {{Po} - {Pl}} )B^{2}}{2\mu \quad L}} & (6)\end{matrix}$

can be substituted into the equation for the velocity: $\begin{matrix}{{Vz} = {\frac{3{fg}}{4{WB}}\lbrack {1 - ( \frac{x}{B} )^{2}} \rbrack}} & (7)\end{matrix}$

The boundary conditions for equation four are

@z=0 ca=0

@x=0 ca=ca0

@x=infinity ca=0

for the limiting case of a small boundary layer of vaporized scentmolecule the solution to equation 4 is: $\begin{matrix}{\frac{ca}{ca0} = {1 - {\frac{2}{\pi}{\int_{0}^{\frac{x}{\sqrt{4{{Dabz}/v}}}}{^{- \xi^{2}}{\xi}}}}}} & (8)\end{matrix}$

This simplifies to: $\begin{matrix}{\frac{ca}{ca0} = {{erfc}\frac{x}{\sqrt{4{Dab}\frac{z}{v}}}}} & (9)\end{matrix}$

The above solution is only valid for small boundary layers where thestream velocity can be considered constant. In order to extend thesolution for larger width gas streams the solution given in equations 8& 9 can be used in an iterative numerical process. In this process thewidth of the stream is divided into a series of thin shells. In each ofthese shells the velocity can be considered constant. Let the thicknessof the shell be represented by dx. The iterative process follows thefollowing steps:

Let i go from 1 to n

1) use the value of ca(i-1) in equation 9 to solve ca(i) at x=x(i)

2) use the value of ca(i) in step 1 to solve for ca(i+1)

The numerical solution was performed using a program written in MATLAB.The program is listed here:

PROGRAM II function y=lmcn(Dab,z,fg) %lmcn for a chamber 3cm × 1.5cm%laminar flow bottom 1 cm is liquid %this function gives theconcentration %profile in a laminar gas stream passing % thru thefragrance container mu=0.000193; xn=0; tcn=0.05; so=0.18; vm=fg*0.25cc(1)=0.684; for i=2:20 xo=xn; xn=(0.1*(i));xxn(i)=((xn−1)/2){circumflex over ( )}2; v = vm*(1−xxn(i)); ss =sqrt((4*Dab*z)/v); er=erfc(xn/ss)−erfc(xo/so) cc(i)=cc(i−1)*(1 + er)so=ss; tcn=tcn+(cc(i)* 0.1); end y=cc

EXAMPLE II

This will illustrate the calculation of the concentration scent moleculeA in the laminar gas stream passing over the liquid fragrance in thefragrance container. As described in the preceding section the solutionis achieved by applying equation 9 iteratively over the full height ofthe fragrance container. Program II which was just listed will executethese steps.

Consider the fragrance container described in FIG. 3 a. The container is3 cm in height 1.5 cm wide and 6 cm long. The bottom 1 cm of thevertical height of the container is filled with the liquid fragrance.Therefore the area in which the air picks up the scent is 1.5 cm by 6cm. We will consider the same example as discussed for turbulent flow.That is pure n-pentane in liquid phase evaporating into and diffusinginto the fresh air stream.

The values of the relevant constants are:

Dab=0.0872 cm²/sec

$\begin{matrix}{\frac{\rho}{\mu} = {6.729\quad {\sec/{cm}^{2}}}} & (10)\end{matrix}$

V_(max)=16.5 cm/sec

Let the value of z be 5 cm. That is we are looking at the cross sectionof the gas stream flowing through the container at 5 cm form theentrance. FIG. 3 d shows the graphical representation of the solutioncalculated for this example. The x axis represents the distance form theliquid surface. The y axis represents the mole fraction of pentane inthe gas stream.

FIG. 4.

A. Distribution of the Scent Molecules in the Gas Stream.

The calculation in example two shows that at five cm there is not aneven mixture of pentane in the gas stream. The same calculation done at6 cm which is the distance to the exit port of the fragrance containeralso shows a similar mole fraction profile with an insignificant amountof additional mixing. The question then arises as to the amount ofmixing which will occur in the laminar gas stream after it exits thefragrance container and is traveling along the tubing.

Its important to determine this because one of the importantrequirements of this system is that if delivers a consistentconcentration of one scent or a mixture of scents to the user. If thisdoes not happen the successful achievement of an olfactory virtualreality will be hampered. The equation and solution of this problem willbe presented here:

In the preceding section the development of the differential equationwhich describes the concentration of the scent molecule in a gas streamas a function of the x and y coordinates was developed. The x and zcoordinates were described in the preceding section. The equation wasderived by writing a mass balance equation for a volume in the gasstream as that volume goes to zero. Then the equations for mass flux inthe x and z directions were substituted into the mass balance equation.Then substituting these expressions for molar flux into the mass balanceequation (equation 1) yields: $\begin{matrix}{{v_{z}\frac{\partial{ca}}{\partial z}} = {{Dab}\frac{\partial^{2}{ca}}{\partial x^{2}}}} & (11)\end{matrix}$

The equation will be solved for the case of a rectangular duct. Thissolution differs from the one in the preceding section because there isno longer a source for the scent molecule. There is no liquid reservoiras there was in the fragrance container. This makes the solution morecomplex. Therefore this equation was solved numerically. The velocity iscalculated using equation 7: $\begin{matrix}{{Vz} = {\frac{3{fg}}{4{WB}}\lbrack {1 - ( \frac{x}{B} )^{2}} \rbrack}} & (12)\end{matrix}$

The algorithm used to solve the equation for ca is:

1) The initial boundary values are the concentration values calculatedfor the gas stream exiting the fragrance container. These values arecalculated using the solution for equation nine, laminar gas flow, andwhose corresponding computer program was listed in Program II.

2) Starting with these initial values the second derivative of theconcentrations of A with respect to variable x is determined.

3) This second derivative is used with the value of Diffusivity Dab andthe velocity to calculate the derivative of the concentration of A withrespect to z.

4) The derivative of ca with respect to z is used with the value of caat z to calculate the value of ca at z+dz.

The computer implementation of this algorithm is as follows:

PROGRAM III function y=lmcn4 (Dab,ze,fg) %lmcn4 for a chamber 3cm ×1.5cm %laminar flow bottomv 1 cm is liqd %this function gives theconcentration %profile in a laminar gas stream after % it has exited thefragrance container mu=0.000193; xn=0; tcn=.0684; so=0.18; vm=fg*0.25cc(1)=0.684; z=6.0 for i=2:40 xo=xn; xn=(0.05*(i));xxn(i)=((xn−1)/2){circumflex over ( )}2; v=vm*(1−xxn(i)); ss =sqrt((4*Dab*z)/v); er=erfc(xn/ss)−erfc(xo/so); cc(i)=cc(i−1)*(1+er);so=ss; tcn=tcn+(cc(i)* 0.05); end while (z) < ze xn=0; z = z+0.1 s0 =0.18; j=2; while (j)<40 xo=xn; d(j) = (cc(j)−cc(j−1))/0.05;dp(j)=(cc(j+1)-cc(j))/0.05; dd(j)=(dp(j)−d(j))/0.1; xo=xn;xn=(0.05*(j)); xxn(j)=((xn−1)/2){circumflex over ( )}2; v =vm*(1−xxn(j)); nc(j)= ((dd(j)/v)*0.1*Dab)+cc(j) ; if j == 2 nc(1) =((d(2)*(0.1)*Dab*(0.1/v))+(cc(1)*0.01))/0.01; elseif j == 39 nc(40)=((dd(39)/v)*0.1*Dab)+cc(40); end j=j+1; end for i=1:40 cc(i) = nc(i);end end y=cc

The use of this mathematical model will be illustrated in the followingexample.

EXAMPLE III

The case considered is a gas stream emerging from the fragrancecontainer described in example II. The conditions existing in thefragrance container and the gas stream flow are the same as those givenin example II. The duct that the gas flows through has a rectangularcross section with dimensions of 2 cm by 1.5 cm. For this example wewill look at the cross sectional concentration profile of pentane in therectangular channel 100 cm beyond the exit of the fragrance container.This is shown in FIG. 4. The x axis is along the vertical dimension ofthe channel. The y axis represents the concentration of the pentane.

It can be seen from this example that even at 1 meter beyond the exit ofthe fragrance container the concentration of pentane in the gas streamis not homogeneous. By applying this same solution to smaller ducts anddifferent scent molecules it can be shown that full mixture of the scentmolecule in the gas stream could not guaranteed to occur with theinvention specified in this document. Therefore a packed bed canister inthe exit flow stream has been implemented to guarantee full mixing. Thiswill be described in the next section.

B. Packed Bed Mixer

One of the distinct features of this invention in comparison topreceding inventions is the unique ability to deliver a consistent andpreselected concentration of different scents to the user. The use ofmathematical algorithms described in the previous sections allow precisecontrol and prediction of the scent delivered to the user. In order toguarantee complete mixing of individual scent molecules as well asmixtures of different scent molecules a packed column is used.

The packed column is downstream form the fragrance containers. All theoutlet tubes from the individual fragrance containers feed into thepacked column. The packed column is chosen because it is well suited tothoroughly mix gas streams especially when the streams are in laminarflow. The invention disclosed in this document can be used with a highvelocity gas turbulent gas flows. However in many applications of thisinvention laminar flow gas streams will be used. Thus the packed columnis used in order to guarantee a fully mixed gas stream delivered to theuser of the device.

One equation governing flow in a packed column is the Darcy's Law(Darcy, H. “Les Fontaines Publiques de la Ville de Dijon,” 1856):$\begin{matrix}{u = {{- \frac{k}{\mu}}\frac{p}{x}}} & (13)\end{matrix}$

Where k is the permeability given by the Ergun equation(Ergun S. “FluidFlow Through Packed Columns,” Chem. Engr. Progress.48,89-94 (1952)). Theequation has different forms for different flow regimes. The criteriafor laminar flow is: $\begin{matrix}\frac{{d(V)}\rho}{\mu} & (14)\end{matrix}$

This is similar to the standard reynolds number formula. However in thecase of packed columns D is the diameter of the particles in the packedcolumn. In the case of packed columns the criteria for laminar flow isthat the number calculated in equation 13 is less than 20.

If the flow regime is laminar the Ergun equation becomes:$\begin{matrix}\frac{\varepsilon^{3}d^{2}}{\alpha ( {1 - \varepsilon} )} & (15)\end{matrix}$

where:

epsilon is the porosity (void fraction)

alpha is a dimensionless parameter which was estimated by Ergunn as 150

EXAMPLE IV

Consider a packed column filled with wire crimps. The column is 10 cmlong and has a radius of 1.4 cm. The diameter of the crimps is 0.4 cmthe viscosity of the gas stream 0.000193 gm/(cm.sec). Let the gas flowrate be 38 cc/sec. Then the calculated reynolds number for the packedcolumn is 16.6 which makes the flow laminar. The superficial velocitythrough the column is 6.7 cm/sec.

Using the Ergunn equation the permeability k is calculated as 0.0011cm². Then substituting these values in the Darcy equation gives a valuefor the pressure drop of 0.17E-3 psi.

C. Mixtures of Scent Molecules

At this point one may raise the question of what scent concentration Caactually means. There are very few commercially used scents that consistof only one type of molecule. Many are complex combinations ofmolecules. Thus representing a scent concentration by a term like is Cais an oversimplification. How can this complexity be accounted for inthe preceding equations. It turns out that even complex scents can berepresented by the above equations without making changes.

The reason for this is that although the scents are complex the relativeratios or mole fractions of the different molecules in the scent remainrelatively constant. This assertion coincides with everyday experience.For example regardless of the temperature, and air pressure the smell ofcigarette smoke smells remarkably similar. the same would hold true formost scent producing objects e.g.the scent of freshly baked apple pie,pine tree scent, diesel fumes do not smell significantly different indifferent geographies at different times of the year.

Therefore one who is practiced in the art can choose to measure anyconvenient molecule from the combination of molecules found in a scent.Then a simple linear relationship exists between the concentration ofthat molecule and the overall intensity of the scent. Thus once thedesired intensity of scent has been chosen then the correspondingconcentration of a convenient molecular component of the scent can bedetermined. Then the above equations can be solved letting Ca, representthe desired concentration of that molecule.

If more than one valve is opened the net concentration of the differentfragrances can also be calculated. If the valves 28 used are simpleon/off valves then the flow Vb through each fragrance container 48 isthe same. Therefore the concentration of fragrance delivered to thenasal tubing 20 is given by:

CFai=Cai/ N

where

CFai=the final concentration of scent i in the nasal tubing

Cai=the concentration of scent in the outlet port 50 from the fragrancecontainer

N=the total number of fragrance containers whose air inlet valves areopen.

In the case of proportional flow valves more sophisticated scent effectscan be achieved. True virtual reality effects with scent can be achievedthat have never been described in any preexisting patents. In the caseof visual virtual reality a basic principle is the two dimensionalrepresentation of three dimensional objects by using shading, size andproportions. The closer an object is the larger it appears. In a similarway the closer one is to the source of a specific scent the more intenseis its smell. In an analogous way to visual virtual reality proximity toobjects can be simulated by adjusting the intensity of the scene towhich the viewer is exposed.

Thus in a movie scene it is possible to depict the relative distances ofdifferent scent emitting objects by proportional flow control valves 28.These can adjust the relative flows through the individual fragrancecontainers 48. Therefore the concentration of each scent in the mixturewhich the viewer smells can be fully controlled. It may be noted thateven with on/off valves proportional flow control can be achieved bywhat is called valve cycling. In this system the valves are turned onand off cyclically. The amount of time the valve is open relative to thetotal cycle time determines the amount of flow through the valve.

This is given by:

Vb′i=(Ton/Tcycle)Vbi

where

Vb′i=average flow rate through valve (i) of air (B)( cm3/min)

Vbi=flow rate through the valve(i) when it is in the open position

Ton=time in the on position

Tcycle=total time of the cycle

Whether proportional flow control is achieved with a true proportionalflow control valve or by cycling an on/off valve the resultantconcentrations of the various scents can be calculated by:

CFai=(Cai) (Vbi)/(Vb1+Vb2+. . . Vbn)

where n=total number of fragrance containers with open inlet valvesCFai, Cai, Vbi follow the same definitions as previously used in thissection.

CFai=the concentration of scent ai delivered to the viewer

Cai=the concentration of scent which is achieved at the outlet of thefragrance container 48

The assignment of relative intensities of scent is based on experimentalstudy of these different scent emitting entities and how their intensityvaries with distance and other environmental factors. It is difficult topredict the intensity based on theoretical diffusion calculations. Thatis because most scents are not merely propelled by diffusion but thereare also complex convective forces. When someone is smoking theynormally blow the smoke into the air, someone wearing perfume may bestanding and walking and this has to be factored by complex convectionterms.

In addition air temperature and the temperature of the entity emittingthe scent are important. A freshly baked pie just brought out from theoven is more easily detected by the scent than one which has beensitting outside for a day. Therefore the relative scent intensities ofcommon objects will be determined as a function of distance and settingby experimental means. These relative intensities can be compiled andused as a database.

Then when a film is previewed the relative scent intensities can beassigned to scent emitting objects or people in a given scene. Thisscent data will then be used to determine the final concentration ofeach scent in the nasal tubing 20 based on the given movie scene. It wasdiscussed earlier that by adjusting flow through the valves whichdeliver the relevant scents the final concentration of each scent can becontrolled. Let the relative scent intensity of scent be represented bythe variable xi which ranges in value from 0 to 1. The scent intensitywhere xi=1 represents the maximum scent intensity, whereas xi=0represents no detectable scent.

In the preferred embodiment the final scent concentration in the nasaltubing will be related to the predetermined scent intensity xi. Thefollowing equation shows Steven's Power Law, which shows the correctconcentration in the air C required to achieve a specific odor intensityxi:

xi=k(C)^(n)

this can be converted to log xi=n log(C)+log(k)

The values of n and k are constants which are experimentally derived foreach scent.

The relative contribution of a specific odoriferous compound in amixture of odoriferous compounds is given by U , which is referred to asodor units:

U=C/Cthrs

Cthrs is the threshold concentration for detection by a human nose.

C is its concentration in a solution

Using Steven's power law the relative odor intensity xi′ in terms of theodor units is given by

xi′=k (UCthrs)

for sub threshold intensities the odor unit U of the whole collection ofcompounds is added:

Um=U1+U2+. . . Un

for supra threshold intensities

Um=k(U1+U2+U3+. . . )n

Another relevant calculation is the just noticeable difference dC inscent concentration which can be detected by an observer is given byWeber's Law:

dC/C=W

where W=0.28

C=the current scent concentration

FIGS. 5 a and 5 b. The Nasal Tubing

FIG. 5 a shows the nasal tubing in detail. It shows the way in which itfits on the wearer's head. The delivery of the scent to the user is viatubing which wraps around the wearer's head and passes underneath theirnose. The tubing has three parts. There is an inlet arm of the nasaltubing 20A which carries the scent from the scent inlet 18 to theportion of the nasal tubing 20B which is located underneath the user'snose. The portion of the nasal tubing 20C leading away from nasal tubing20B is the exhaust portion.

This tubing leads into a scent scrubber 38 which is a box with acharcoal filter which removes the fragrance chemicals from the exhaustedair. The portion of the nasal tubing 20B, which is located underneaththe user's nose, has a 90 degree branch (19 in FIG. 5 b) which liesbelow the two nostrils. This branch is located on the top side of thetubing which is closest to the nostrils.

In order to calculate the quantity of the gas and scent delivered to theuser of this invention it necessary to calculate the flow through a tee.The tee and its relevant variables are illustrated in FIG. 5 b. A tee isa branch off a tube which is at 90 degrees to the main line. The branchwhich has velocity V@ corresponds to part 19 in the preceding figure.

That is 19 is the branch which is situate below the nostrils. There aretwo flow conditions to consider. One condition is turbulent flow thesecond is laminar flow. The case of turbulent flow through a tee is welldescribed in the literature. The case of laminar flow is more complexand has only a few references in the literature. However in thepreferred embodiment laminar flow will frequently be the flow regime inthe system.

Therefore the solution for laminar gas flow through a tee will bepresented. The generalized energy equation for the flow system is:$\begin{matrix}{\frac{E}{t} = {{\frac{Q}{t} - \frac{W}{t}} = {\int_{A}{{\rho ( {\frac{v^{2}}{2} + {gz} + u} )}( {v \cdot N} )}}}} & (16)\end{matrix}$

One group that has studied this problem (Jamison D. K. and VillemonteJR. Junction Losses in Laminar and Transitional Flows. Proc. Am. SocCivil Engineers. Hydraulics Div.July 1971, pg. 1045-1063) hasreorganized this equation so that the heat loss terms are equated to thehead loss terms. The equation for the total loss through the tee can beexpressed in terms of kinetic energy and head losses through the twobranches of the tee: $\begin{matrix}{{hFm} = {{( {\frac{\rho}{\gamma} + {\alpha \frac{V^{2}}{2}g}} )_{1}\frac{Q1}{Qm}} + {( {\frac{\rho}{\gamma} + {\alpha \frac{V^{2}}{2}g}} )_{2}\frac{Q1}{Qm}} - ( {\frac{\rho}{\gamma} + {\alpha \frac{V^{2}}{2}g}} )_{m} - {{hf1}\frac{Q1}{Qm}} - {{hf2}\frac{Q2}{Qm}} - {hfm}}} & (17)\end{matrix}$

The total losses from the branches 1 and 2 to the section they convergeon are:

for branch 1: $\begin{matrix}{{hF1} = {( {\frac{\rho}{\gamma} + {\alpha \frac{V^{2}}{2}g}} )_{1} - ( {\frac{\rho}{\gamma} + {\alpha \frac{V^{2}}{2}g}} )_{m} - {hf1} - {hfm}}} & (18)\end{matrix}$

for branch 2: $\begin{matrix}{{hF2} = {( {\frac{\rho}{\gamma} + {\alpha \frac{V^{2}}{2}g}} )_{2} - ( {\frac{\rho}{\gamma} + {\alpha \frac{V^{2}}{2}g}} )_{m} - {hf2} - {hfm}}} & (19)\end{matrix}$

then the terms for the total losses in the branches can be substitutedinto the equation for the total loss in the tee: $\begin{matrix}{{hFm} = {{{hF1}\frac{Q1}{Qm}} + {{hF2}\frac{Q2}{Qm}}}} & (20)\end{matrix}$

This can be rewritten in terms of a loss coefficient which is defined asa coefficient when multiplied by the velocity head gives the total loss:$\begin{matrix}{K_{Fm} = \frac{\frac{h_{Fm}}{V_{m}^{2}}}{2g}} & (21) \\{K_{F1} = \frac{\frac{h_{F1}}{V_{1}^{2}}}{2g}} & (22) \\{K_{F2} = \frac{\frac{h_{F2}}{V_{2}^{2}}}{2g}} & (23)\end{matrix}$

The following equation is valid when the cross sectional areas of thebranches of the tee are equal: $\begin{matrix}{K_{Fm} = {{K_{F1}( \frac{V_{1}}{V_{m}} )}^{3} + {K_{F2}( \frac{V_{2}}{V_{m}} )}^{3}}} & (24)\end{matrix}$

Jamison and Villemonte (Jamison D. K. and Villemonte JR. Junction Lossesin Laminar and Transitional Flows. Proc. Am. Soc Civil Engineers.Hydraulics Div.July 1971, pg. 1045-1063) determined the losscoefficients for laminar divided flow in a tee. Let Vm be the flowentering the tee, V1 the flow exiting the straight part of the tee, V2the flow exiting the side branch of the tee. Let Rm, R1, R2 be thecorresponding reynolds numbers for those three segments. This sidebranch will be the nasal branch described above.

For the main line entering the tee:

the loss coefficient Km is:

For the main line entering the tee: the loss coefficient Km is: 2100/Rmwhen 75% of the flow passes straight through the tee 3330/Rm when 25 or50% of the flow passes straight through the tee for the straight exitsegment the loss coefficient K1 is: 6400/R1 when 25% of the flow passesstraight through the tee 3650/R1 when 50% of the flow passes straightthrough the tee 2100/R1 when 75%or100% of the flow passes straightthrough the tee

for the branch exit segment

the loss coefficient K2 is:

7000/R2 when 25%,50%, 75% or 100% of the flow passes straight throughthe tee

EXAMPLE IV

In this example a sample calculation of flow through a tee will bedemonstrated. The method of solution will be to solve equation 21 forV1. The term Vm is predetermined for the calculated flow through theentire system. This was shown earlier. The nasal tubing makes littlecontribution to the overall resistance of the system and thus the netflow rate. However the contribution of the tee could be calculated ifdesired.

The term V2 can be written in terms of V1. That is V2=Vm−V1. In additionthe loss coefficients can be written as known constants divided by therespective velocity terms through the different limbs of the tee, Thusequation 21 can be written so that the only unknown in the equation isV1. Given its form however it is hard to solve this equationempirically. Therefore the solution is found by a numerical iterativesolution starting with small values of V1 and iteratively increasing thevalue of V1 until convergence occurs. A computer program to produce thissolution is given here:

PROGRAM IV function y=tflw(fg,ra,rb) %tf lw calculate flow in tee %vt istotal input %fg is the gas flow % ra and rb are the branch radiica=2*ra*(1/0.1486); cb=2*rb*(1/0.1486); vt=fg/(pi*(ra{circumflex over ()}2)) rt=vt*ca; vv=0.05*vt; va=0.9*vt; dif=100; ii=0 while dif>0.5ii=ii+1; va=va−vv if (va/vt) > 0.74 mk=2100; ak=2100; elseifabs((va/vt)−0.5)<0.25 mk=3300; ak=3650; elseif (va/vt)<0.5 mk=3300;ak=6400; end km=mk/(ca*vt); ka=ak*((va/vt){circumflex over ()}3)/(ca*va); kb=7000*(((vt−va)/vt){circumflex over ( )}3)/(cb*(vt−va));kt=ka+kb; dif= sqrt((km−kt){circumflex over ( )}2) end count=ii y=va

In this example the computer program is used to solve a tee flow problemwith the following physical parameters:

Vm=inlet flow into the tee=21 cc/sec

V1=straight flow out of the tee

V2=flow from the branch of the tee

the radii of all three segments are 1 cm

the calculations are done for 1 atm pressure at 21C.

The calculated flow through the straight portion of the tee is 7.3cm/sec. Then the flow through the branch is 13.7 cm/sec.

FIG. 6 The Controller System

FIGS. 6, 6 a & 6 b: Electronic Circuitry And Algorithm to SynchronizeScent Release with a Analog Video Signal

FIG. 6 a shows the entire electronic circuitry which allows themicrocontroller to control the scent releasing device in conjunctionwith an analog video signal. The input 88 to the free standingmicroprocessor 34 is a VCR or television 39 or other videographic NTSCsignal (or other compatible signal). FIG. 6 shows a magnified view of acommercially supplied microprocessor which can be used in the circuitshown in 6 a. The input can also come from a larger motion picturegenerating device such as that used in a movie theatre or drive-in. Aschematic of the video signal is shown in the figure. It can be seenthat there are different digital synchronization signals (such as thefront porch or back porch, as well as analog video signal. Each one ofthese signals has a characteristic single voltage or voltage range. Thestandard video signal goes from one volt peak to peak. This voltage isbroken up into 140 even divisions referred to as IRE's( Institute ofRadio Engineer's) units. There are 7.1429 millivolts per IRE.

Referring to the figure it can be seen that the front porch correspondsto −40 IRE's. In addition it only occurs once in the video line for agiven frame. Thus the voltage of −40 IRE could be used as a way to countframes.

Other portions of the signal could be used as well. The video signal isfed into an analog to digital converter 89 (labelled as ADC 0831). Inthis example an 8 bit serial A/D converter is used. The voltage input 88into the A/D converter 89 gets converted into a digital output, which isfed into the microcontroller 34. This is depicted by the lines going topin 1 and pin 2. The digital data is in serial form. The data is latchedonto the microcontroller using the rising or falling edge of a clocksignal line in the typical way that a shift register works. This digitaldata becomes the input variables for software onboard themicrocontroller which then looks up the correct open /closed settingsfor the 31 valves for a given video image. This data is stored in a 32bit variable called seq(i).

The algorithm used by the onboard software to find the variable seq(i)is discussed in the description of FIG. 6 b. Each bit from the 32 bitword “seq(i)” will be used to control 31 separate valves 28 and onecompressor 30. This is accomplished by first using 8 bit serialshift-registers. Three pins from the BSII microcontroller 34 areconnected to each shift register 92. Since there are 16 I/O pins on theBSII microcontroller 34, and three pins are dedicated to each shiftregister then 5 shift registers can be controlled by the microcontroller34. Since each shift register 92 has eight possible outputs it ispossible to control forty separate valves 28 with one microcontroller34.

As shown in FIG. 6 a BSII pin 0 connects to the “data in” port of theshift register 92. BS pin 1 connects to the clock pin labelled “clk”.The third connection is from BS pin 2 to the “latch” pin on the register92. Thus 8 bits of data can be “latched on” to the 8 output pins Qathrough QH. Until new data is latched onto the shift register theseoutput pins QA through QH remain in the data states that they are set.The output from these pins goes to an industrial power switch 94labelled LM1921. It can be seen from the figure that the output from theshift register goes to pin 5 of the DC switch 94, which turns the switchon or off. The supply voltage goes through pin 1 Vcc. It passes outthrough pin 2 which leads to Vout.

In the figure Vout is then connected directly, via the controller wires80 a and 80 b, to the alloy wire 76 which is part of the valve system.Thus when the power switch is activated 94, the alloy wire 76 isenergized and the valve 28 is opened which thus allows compressed airthrough it. This in turn leads to the delivery of the specified scent.It can also be seen that one of the DC power switches 94 activates apower relays 96 which in turn activates a heavy duty power solenoidwhich can complete a 120 V single phase AC circuit to power thecompressor 30 The compressor needs to be turned on any time any valves28 are opened.

System for Digital Images Derived from an Electronic Computational andVideo Display Device

The same system described in FIG. 6 a can be used to allow scentdelivery to be synchronized with the display of digital images. Thedigital images are being displayed by a digital signal processorincluding but not limited to a micro, mini or mainframe computer ormicroprocessor based video gaming system. The images can include CD ROMbased images, individual images stored on a file storage system read bythe computer or video images which have been digitized.

In general all these images are stored in one of several establishedfile formats including but not limited to TIFF, GIFF, TGA, BIF formats.In these file formats there is space allocated for group identificationand sequence information. That is each image in a sequence of images isassigned a number which indicates its order in the sequence. In additionthe frames can be a part of a sequence of frames which forms a movingimage (i.e a movie). The membership of a sequence of frames in aparticular movie can also be placed in the coding in the initial blockof bytes assigned to that image. Therefore as the frame is beingdisplayed the information about what movie it is part of and what frameit is transferred directly to the microprocessor 34 described in FIG. 6a.

The simplest way of doing this is to provide software to be used on thecomputer which strips each frame of these two pieces of data: framenumber and movie membership. Then a serial port(RS232) from the computercan be connected to the microprocessor via pins 0,1, and 2 in exactlythe same way that the A/D convertor is connected to the microprocessoras described in FIG. 6 a. Using this connection serial digital data canbe load into the microprocessor. The data is assigned to the variables“count” and “button” that were described in the section for FIG. 6 a.The data can then be used by on the on board software in the same way asdiscussed in the description for FIG. 6 a. The software outputs thevariable seq(i) which sets the 31 valves in the open or closed positionfor the current video frame being displayed.

FIG. 6 b shows a flowchart which shows the generalized sequence oflogical steps which are performed by the software used to run anymicrocontroller or computer device which could be used to control thecompressor and the valves. Once the voltage data is received by themicrocontroller it is assigned to a measuring variable called “VOLT”.The value of VOLT is tested to determine if it corresponds to any of thecharacteristic voltages in an NTSC frame described in section 6a. If itdoes, the variable “COUNT” which corresponds to the current frame willbe incremented by one. In the case of digitized images the variable thatis read in by the software is the frame number currently beingdisplayed. As in the case of the analog signal the variable COUNT isincremented by one.

The variable “BUTTON” contains the data which is entered by the personpushing a keypad interfaced with the microcontroller. This data is anumber which is a predefined code for the specific video to be shown.The value for BUTTON can also come directly from a video digitizingdevice. In that case the value for “BUTTON” comes from the informationat the beginning of the digital record for a specific video. Thisinformation specifies the membership of a specific image in a group ofimages (i.e. a movie). These variables were mentioned in thedescriptions of FIG. 6 a.

The next step is to use the value of “BUTTON” as one of the indices ofan n x m matrix called “FRAME(i,j)”. The index i is replaced by thevalue of the variable button. Thus the i'th index refers to a row in thematrix FRAME which contain frame values for the moving image which wasindexed by the variable BUTTON. The value of FRAME(BUTTON,O) for thespecified movie, is the starting address for the series of frameintervals that make up the film. Each frame interval is defined as agroup of video frames where the corresponding valve settings areconstant. Each video can be divided up into a series of frame intervals:FRAME(BUTTON,j)→FRAME(BUTTON,j+1). The next step in the algorithm is todetermine which interval the current frame falls intoFRAME(BUTTON,j)→FRAME(BUTTON,j+1). 2000 bytes following the address forFRAME(BUTTON,0) are available for the variablesFRAME(BUTTON,0)→FRAME(BUTTON,n). The value of n, for a specific movie,is the total number of frame intervals where valve settings for thisinvention remains constant.

The value of each variable FRAME(BUTTON,j) is the value of the finalframe of that specific frame interval. Thus the algorithm tests thevalue of the current frame: count to determine which interval it fallsinto: FRAME(BUTTON,j). The value of j is then used as the index of thevariable “ADDRESS”(j). The value of ADDRESS(j) contains the startingaddress of a 32 bit variable “SEQUENCE(j)”. SEQUENCE(j) is a series of32 bits whose values are either one or zero which corresponds to an onor off state for each valve 31 valves and one compressor.

The number of addresses needed to represent all the sequence variablesis limited because all possible permutations of on/off states for the 32valves would not occur. Only a limited number of valves will be open atany time. For example indoor scents would not be used in combinationwith outdoor scents. Another example is that an indoor car smell wouldnot be mixed with the scent of wood burning in a fireplace.

In the preferred embodiment the 32 bit data, that is represented bySEQUENCE(j), is then sent to the output pins of the microcontroller.Those bits which are output are used to switch on or off the 31 valvecircuits and the one compressor circuit. This is done by turning relayswitches on or off. This will in turn allow the desired scent orcombination of scents to be produced and delivered to the user insynchrony with the video image being displayed.

FIG. 7 The Scent Scrubber

FIG. 7 shows the scrubber 38. It receives its input from the nasaltubing 20C which leads into the scrubber inlet 124. The scrubber inlet124 feeds into the filtration chamber 126 filled with specializedfiltration materials. The materials have the specific property that theycan remove odors from the air. One common type of filter material isactivated carbon. However there are other filter materials which canalso be used. The air is then exhausted through the scrubber outlet 128.

Other Embodiments

Public Theatre

Description and Operation

The device described in the main embodiment can be modified so that itcan be used in a place where many people view the movie at the same timesuch as a public cinema, passenger airplane or drive-in theatre. FIG. 8shows this alternate embodiment. All the elements of the systemdescribed in the main embodiment are kept.

However additional parts are added. In addition the magnitude of all thecomponents which create the scent including the compressed air inlet hub26, inlet valve 28, compressor 30, bleed valve 32, scent scrubber 38,liquid fragrance air inlet 42, liquid fragrance holder 48, increased inmagnitude to accommodate a full room of viewers.

The new components, as shown in figure eight, include a main boostercompressor 98 which is fed by the outlet common tubing packed column 16.The output from the main booster compressor 98 goes into a main manifold112 which splits the gas stream into n equal streams. Where n is thenumber of rows in the theatre or other convenient grouping of seats.Then each of these split streams is fend into a secondary manifold 114which splits the incoming stream into m streams, where m represents thenumber of individual seats in the designated row or other grouping ofseats which is being used.

Then each of the streams coming out of the secondary manifold 114 isdelivered to an individual in the theatre. The secondary manifold 114divides the input flow into the individual scent inlets 18 for theindividual nasal tubing 20 for each patron.The scent is exhausted fromeach patron in the same way as it was in the preferred embodiment. Thatis the output from each theatre patron's nasal tubing 20 c feeds into acommon exhaust line 130 which is situated in a convenient place such asin the floor below the seats. Then this line feeds into the scrubber 38.

The electronic control system for this alternate embodiment will besimilar to that described in the main embodiment in FIGS. 6, 6 a, and 6b. However instead of relying on a video input signal to themicrocontroller, an internal clock timer in the microcontroller can beused. Specifically the projectionist would input the code for the movieinto the microcontroller just as it was described earlier for an NTSCprojection device.

However in this case no NTSC video input would be needed. Instead theinternal clock timer could be used to precisely calculate which frame ofthe movie was currently being projected. That is because in this casethere is no stopping or starting of the film it is always shown over thesame period of time. The rest of the electronic circuity, as describedin FIGS. 6 a, 6 b and 6 c of the main embodiment, will be the same.

Other Nasal Interfaces—Description and Operation

Turning to FIG. 9 a, this alternate embodiment will refer to the otherdevices which can be used to deliver the output from the scent inlet 18to the wearer's nose. They include a face mask 120 which fits over thewears nose and mouth as shown in FIG. 9 a. The dimensions of the mask is9.0 cm at the base. The base refers to the base of the triangle belowthe mouth. The top of the triangle which goes over the bridge of thenose is 4 cm. The sides of the triangle are 14 cm in length. The maskcan be made out of any biocompatible substance such as vinyl, orpolyethylene. The mask can have a metal crimp over the bridge of thenose to help hold it snugly. The scent inlet 18 feeds directly into aface mask outlet tube 184. The scent is exhausted with the help of ascrubber booster 138 which leads directly into the scent scrubber 38.

In FIG. 9 b another device is the nasal mask 122 whose input also comesfrom the scent inlet 18 and which fits snugly over the wearer's noseincluding the nostrils as shown in FIG. 9 b. The dimensions of this maskare that of a triangle whose base is 6 cm and sides are 7 cm in length.Within this same mask is a simple mask outlet 136 which carries thescent laden air out to the scent scrubber 38. However the pressure inthe mask itself is close to atmospheric pressure therefore there is nodriving force to push the air through the mask outlet 136. Therefore thesystem has the same inline vacuum pump (scrubber booster 138) describedin FIG. 9 a. This pump draws air from the mask and forces towards ittowards scrubber 38.

FIG. 9 c shows a nasal interface that is not physically connected to thewearer but is proximal to wearer's nose. The figure shows a user who isseated so that the nose is adjacent to a scent delivery system. Thesystem consists of a small nasal bridge 142 which is 4 cm in lengthwhich the user can position his nostrils over. It has one output hole144, 1 cm in diameter which terminates 2 cm below the nasal septum. Onthe top of the bridge is a suction hole 146, 1.5 cm in diameter, whichdraws the scent laden air which was emitted by the output holes 144. Thescent delivery system is supported by a hollow metal support 140 whichcarries flexible tubing which carries gas towards the hole 144 and theother tube draws gas away from the suction hole 146. There is a scentstand vacuum pump 188 downstream from the suction hole 146 which createsthe pressure gradient to draw the air into the suction hole 146 andpushes it towards the same scent scrubber 38 which was described in themain embodiment.

Other Fragrance Inlet Valves—Description and Operation

In the preferred embodiment it was stated that any type of electrical,pneumatic or mechanical valve could be used as the inlet valve 28 forthe fragrance holder 48. The inlet valve 28 can be an on/off valve or aproportionally controlled valve. In this embodiment a different type ofvalve is described based on the flapper type valve. FIGS. 10 a, 10 b,and 10 c show this embodiment. It consists of a hollow body 160 with oneflapper valve inlet 162 which comes directly from the compressor 30 andmultiple flapper outlets 164 each of which feeds a separate fragranceair inlet 42 as described earlier in the preferred embodiment.

Inside the hollow body 160 there is a gang of flapper valves 148 whichare arranged radially around a center spindle 166 as shown in FIG. 10 b.FIG. 10 c shows how each flapper valve 148 is fixed at its base 150, byits attachment to the center spindle 166, about which it can bend. Atthe other end of the flapper valve 148 is valve tip 152 which fitssnugly into a flapper valve seat 154. The flapper valve seats 154 arealso situated in a radial array on the inside of the hollow body 160.Each flapper valve seat 154 overlies one flapper valve outlet 164 sothat when the valve tip 152 is lifted off the valve seat 154 air flowsthrough that particular flapper outlet 164 and into a fragrance airinlet 42 (as described in FIG. 3 a).

The flat metal leaf 151 that forms the body of this flapper valve has aninherent spring tension much like a leaf spring. This spring tensionnormally keeps the valve tip 152 pressed snugly against the valve seat154. Thus the valve is normally in the closed position. On the otherside of the valve tip 152 there is attached a valve opener 158 made froma dynamic alloy wire such as Flexinol (R).

The electrical connections for the valve can be seen by referring backto FIG. 10 a. The other end of the valve opener wire 158 is attached toa support hub 168 which is mounted on the center spindle 166. Thesupport hub 168 can be made from any electrical insulating material. Toactivate the valve opener 158 wire it must be electrically activated.There is a wire harness 172 which enters the hollow body 160 through anair tight port 170. Each wire carried by the harness 172 is connected toa different valve opener 158 at its attachment to the support hub 168.The center spindle 168 is attached to a separate electrical wireconnector 174 which leads to the outside of the hollow body 160.

The other end of each wire in the harness is in series with theelectrical circuit which includes the DC power switch 94 which wasillustrated in FIG. 6 b. The other end of the circuit is attached to theelectrical wire connector 174. This is connected to the same electricalground that the switch 94 power source is grounded to thus completingthe circuit through the valve opener wire 158. Thus when the DC powerswitch 94 is activated the valve opener 158 is activated which pulls thevalve tip 152 off the valve seat thus allowing the compressed air cominginto the hollow body 160 through the flapper inlet 162 to travel outthrough that valve and into the designated fragrance holder 48.

Conclusions, Ramifications, and Scope

Accordingly, it can be seen that the invention provides for an automatedsystem for providing a user with a complex combination of scents in anypossible sequence. The large number of scent combinations is achievedwith an array of scent holders and valves which can mix many possiblecombination of scents. Furthermore the invention directly delivers thesescents to the user's nose by way of a conduit and then rapidly drawsthem away. Thus this system is differentiated from existing scentemitters by virtue of the fact that the scent is conducted directly tothe user rather than being convected and diffused through the air. Thusrapid changes in scents or combinations of scents can be achieved incontradistinction to preexisting systems. In addition the inventionallows this sequence of scents to be delivered in coordination withvideo images and or music, such as movies, video games, or music bymeans of a programmed microcontroller or computer.

Although the description above contains many specificities, these shouldnot be constructed as limiting the scope of the invention but as merelyproviding illustrations of some of the presently preferred embodimentsof this invention. Various other embodiments and ramifications arepossible within it's scope. For example this system can have much largernumber of fragrance holders and valves. The valves would be under directcontrol by the user. Thus a perfumer could rapidly experiment with alarge number of scent combinations without physically mixing theindividual liquid fragrances. In addition the final concentration of thecomponents in the final mixture would be immediately known to theperfumer simply by recording the valve setting. In this applicationproportional flow control valves would be desirable.

This invention could also be modified to produce scents in conjunctionwith music alone rather than video images. In this case the output froma CD player or cassette player would be fed into the microcontroller. Inthe case of the CD output there is an embedded signal which indicatesthe track and section of the CD which is being played. The voltageoutput from a cassette player can be used to indicate the beginning andend of the tape as well as specific pieces of music. In addition to theelectronic timer and the speed of the tape player, the exact position onthe tape can be available to the microcontroller. This will then lead tothe emission of the preprogrammed combination of scents to accompany themusic.

Another use of the system would be as an adjunct to sedation or anxietytreatment for patients, whereby a specific scent or a combination ofscents which are known to produce anxiolysis could be used with orwithout soothing video images or music. Another use of the system wouldbe for the burgeoning field of aroma therapy. In this case thearomatherapist could preprogram a specific sequence of scents for theirpatient to smell over a specific period of time.This embodiment of theinvention would not require the video or music interface to thenicrocontroller.

Thus the scope of the invention should be determined by the appendedclaims and their legal equivalents, rather than by the examples given.

What is claimed is:
 1. A gas conducting system which delivers scentedair directly to a human being's nose by a conduit, said systemcomprising: (a) a compressor which delivers compressed air to an arrayof valves; and (b) fragrance containers to which said valves deliversaid compressed air; and (c) a single conduit for delivering scented airfrom said fragrance containers to the human being's nose.
 2. The gasconducting system of claim 1 wherein said array of valves is controlledby a microprocessor.
 3. The system of claim 2 wherein the saidmicroprocessor receives input from an audio or video generating machineand coordinates control of said valves to provide predetermined scentedair to the human being to complement the audio and visual output.
 4. Thesystem of claim 1 wherein said conduit ends in a perforated tubepositioned below the human's nose.
 5. The system of claim 1 wherein saidconduit ends in a mask which covers the human's nose.
 6. The system ofclaim 1 wherein said conduit terminates in a open ended tube supportedby a stand which is positioned below the human's nose.
 7. The system ofclaim 1 where said conduit divides into multiple branches each of whichdelivers said scent carrying air to a different human being by means ofa single conduit to said human being.
 8. The system of claim 1 whereinsaid conduit has a nasal interface positioned at said nose to allowscented air to be delivered to said nose, said system further comprisinga scrubber and an outlet conduit which connects said nasal interface tosaid scrubber wherein said scented air passes through said nasalinterface, through said outlet conduit and to said scrubber due to saidcompressor.
 9. The system of claim 8 wherein said nasal interface is aTee.
 10. The system of claim 8 wherein said nasal interface is a facemask.
 11. The system of claim 8 wherein said nasal interface is a nasalmask.
 12. The system of claim 1 wherein said conduit passes under thenose and continues to a scent scrubber to remove the scent from the air,and the conduit has an opening positioned below the nose to allowscented air to travel to the nose wherein said scented air passesthrough said conduit and to said scrubber due to said compressor.
 13. Amethod for emulating the scent associated with a specific visual scenecomprising: a) assigning numerical values of intensity to scentgenerating objects based on the specific environmental conditionsincluding distance from an observer, temperature of the object andconvection towards the observer; b) producing a scent utilizing amathematical algorithm and an accompanying computer program forcalculating the proper concentration of scent molecule in a gas streamwhich will produce said scent intensity at the wearer's nose; and c)production of said proper scent concentrations at an observer's noseusing a set of mathematical algorithms and the accompanying computersoftware to precisely calculate the resultant concentration profile ofscent molecules in a gas stream for the conditions of turbulent flow andlaminar flow.
 14. An apparatus for bringing scented air in closeproximity to a human's nose and then quickly exhausting said air awayusing a conduit comprising: a) a single conduit for delivering scentedair to a human's nose; b) an inlet means positioned near the nose whichcontains an opening which allows a portion of said scented air to exitthe conduit and reach the nose by convection and diffusion; and c) anoutlet means of said conduit which contains an opening near the nose toexhaust the gases away from the nose.
 15. A gas conducting system whichdelivers a combination of scents directly to a human being's nose by aconduit, said system comprising: (a) a compressor which deliverscompressed air to an array of valves; (b) fragrance containers to whichsaid valves deliver said compressed air; (c) a mixing means forcollecting the scent carrying air from said fragrance containers andforming a mixture of scent carrying air; (d) a conduit for deliveringsaid mixture of scent carrying air to the human being's nose, saidconduit has a nasal interface positioned at said nose to allow scentedair to be delivered to said nose; and (e) a scrubber and an outletconduit which connects said nasal interface to said scrubber whereinsaid scented air passes through said nasal interface, through saidoutlet conduit and to said scrubber.
 16. The system of claim 15 whereinsaid nasal interface is a Tee.
 17. The system of claim 15 wherein saidnasal interface is a face mask.
 18. The system of claim 15 wherein saidnasal interface is a nasal mask.